Application of Steel Pipe Pile Composite Soil Nailing Supporting Combined Foundation Underpinning Technology

Abstract

Power tower is danger when it is located on the top of slope of foundation pit. Composite soil nail technique had been used broadly in pit supporting in different situation except for building and structures nearby. Using foundation underpinning technology, the additional loads of structures can be transferred and bring about stabilization of slope. With the development of underpinning technique, more and more steel pipe pile should be drill near buildings and structures. The excavation of deep foundation pit lead to security risks when power tower near the pit. Based on the composite soil nail technology and foundation underpinning technology, the deep foundation pit supporting method had been proposed. In the method, the steel pipe pile composite soil nailing wall supporting technology had a role of supporting for the vertical excavation of deep foundation pit, simultaneously the foundation of power tower is stabled by underpinning pile and transform the loads into deep soil using steel pipe pile. The engineering example provide better technical reference for similar projects. I. INTRODUCTION With the speeding up of urbanization, all kinds of civil construction and public transportation infrastructure increases rapidly, the development and utilization of underground space is increasing in the city, and some of the engineering construction approaches for high power tower. The foundation pit excavation in underground engineering construction is easy to cause deformation of soil, leading to differential settlement of the power tower, which will lead to the overall stability of the transmission tower and large transmission security hidden danger, even catastrophic consequences. One power steel tower is near the new municipal engineering excavation. The excavation depth of pit is about 9.0m under natural ground. Due to urgency and narrowly limited time schedule, the tower should be protected when foundation pit excavation.The tower foundation generally designed with four independent shallow foundation, two basic tensile, compression of the other two bases.